KATHERINE (MERRILL) LAMBERT, of Naples, Florida and Chestnut Hill, formerly of Hingham, died on Tuesday, Sept. 7th at her summer residence in Chestnut Hill after a long and courageous battle with acute leukemia. She was 64. Born in Cambridge, MA, she was the daughter of Katherine (Park) Merrill and the late Dr. Dudley Merrill.She attended Shady Hill School, Beaver Country Day School, Smith College and Columbia University Graduate School of Social Work. After obtaining her MSW she worked in family and marriage counseling and as a psychiatric social worker. She was an avid sports woman, athlete, sailor and bridge enthusiast. She, and her husband of 42 years, Brent W. Lambert, MD reside in Naples, FL. and have summered in Chestnut Hill for the past 4 years. Prior to moving to Chestnut Hill they were Hingham residents for over 30 years.Mrs. Lambert served in numerous leadership positions in the Church of Jesus Christ of Latter Day Saints in Hingham, including a full time mission for two years to northern Ohio. She also worked with her husband as a medical missionary in Kenya. She was involved in numerous volunteer community services throughout her life.In addition to her husband, she leaves her four children; Erika P.L. Finlayson and her husband Sam Finlayson, MD of Hanover, NH, Luke M. Lambert and his wife Rebecca of Norwell, Kristin L. Westergard and her husband Rob of Norwell and Rebecca W. Lambert, MD and her husband Jon Sonne, MD of Naples, FL. Also survived by 16 grand-children.Funeral Services Saturday, Sept. 11th at 10:30 AM at The Church of Jesus Christ of Latter Day Saints, 379 Gardner St., Hingham.Friends may visit at the church, prior to the service on Saturday from 9-10 AM.In lieu of flowers, donations may be made in her memory to the Dana-Farber Cancer Institute, 44 Binney St., Boston, MA 02115.The interment will be in the Hingham Cemetery.